[NEED HELP] cant start the game/ session lock problem

when i try to start the xonotic.exe i get the fallowing error: btw the game is installed in the documents directory
session lock c:\users\/xonotic/lock could not be acquired. Please run with -sessionid and an unique session name. Reply

Before you start the game, in your game directory, try to delete the files with names beginning with "lock". And then start the game. Reply